ALBANY -- How far can state government go in keeping tabs on its employees?

That's the question a mid-level appeals court will consider in the wake of a lawsuit filed by the New York Civil Liberties Union against the state Labor Department, in the case of a fired state worker who was tracked with a GPS device that investigators secretly attached to his personal car.

"GPS technology involves an unprecedented degree of government intrusion," said Corey Stoughton, the NYCLU lawyer representing Michael Cunningham, a former state Department of Labor training manager.

Cunningham's battle with the agency, first reported in the Times Union in 2010, began years ago with his contention that he was punished for blowing the whistle on pressure placed on employees to attend a prayer breakfast sponsored by then-Gov. George Pataki.

The NYCLU lawsuit is focused only on the GPS tracking. It believes the surveillance, which was done without a court warrant, violated state constitution protections against unreasonable search and seizure.

Stoughton, in a hearing Thursday before the Appellate Division Third Judicial Department, said she wasn't arguing that Cunningham get his $115,000 job back, but that he should receive another hearing without the GPS-based evidence.

"It entails a massive invasion of privacy," she said.

State officials tracked Cunningham's whereabouts by secretly attaching a GPS device to his BMW.

The electronic tailing went beyond what would normally be termed Cunningham's work hours, since the device was on for 24 hours a day, seven days a week. They even tracked him on a multi-day family vacation.

Kate Nepveu, an assistant solicitor general, said the state realized the GPS tracking was intrusive, but Cunningham's pattern of misconduct and the difficulty of constant in-person surveillance justified the technique.

Cunningham's claim that he worked odd hours at his job helped explain the weekend tracking, Nepveu added..

There was some disagreement among the lawyers as to whether the GPS could have been turned off during nights and weekends.

"The device could not be turned off," Nepveu said when asked by the court.

Stoughton, though, claimed investigators could have turned it off, and that the state didn't exhaust its options for non-GPS surveillance.

"It's that ability to monitor your movements 24 hours a day," Stoughton said after the hearing.

Justices may rule in six weeks, she said. Options include: upholding the GPS tracking or sending Cunningham's firing back to the state for another hearing.

Cunningham couldn't be reached for comment Thursday.

The Court of Appeals, the state's top court, ruled in an unrelated case that police must get a warrant before using a GPS device to track suspects. The U.S. Supreme Court will hear a case this fall.